Theme - Nutrient Flux Flashcards
What is an autotroph?
Name the three types of organism.
An organism that meets its own energy requirements.
- Algae
- Lower plants (bryophytes: mosses)
- Higher plants (flowering plants) … except those that at parasitic
What is a heterotroph?
Name the three types of organism.
An organism that needs others to meet its energy needs.
- Slime moulds
- Fungi
- Animals
What is the simples form of carbohydrate energy store?
Give a named example.
A monosaccharide sugar.
Example: fructose, ribulose
What is a disaccharide?
Give a named example.
It is a pair of sugar molecules that have joined up.
Example: sucrose, lactose, maltose
What is an implication of mono- and di-saccharide sugars that free-float in cells?
They alter the osmotic potential of the solution which can impact other cellular processes
What is fructans an example of and where is it normally found?
It is an oligo-saccharide (a carbohydrate made up of a few sugar molecules).
It is the main storage compound in some plant species.
Explain what a polysaccharide is and where it is found.
It is a carbohydrate made up of many sugar molecules, used as the main energy store in many organisms.
Starch and inulin are examples found in plants.
Glycogen is the form found in animals.
What is TAG and what is it used for?
Triacylglycerol is a lipid (fatty acid) used for long-term energy storage
What is TAG made up of?
3 long chain fatty acids linked by ester to a glycerol molecule
What is the benefit of a TAG with 50 carbon atoms over a polysaccharide?
Polysaccharide is insolube, bulky and solid.
TAG is liquid so a more useful form of storage and more efficient use of space.
Generally which compounds are used for short, medium and long term energy storage?
Short - monomers - monosaccharides like fructose
Medium - polysaccharides like starch or glycogen
Long - lipids like TAG (triacylglycerol)
Name three minerals needed by plants to survive.
Nitrogen, potassium, phosphorus
What are the three approaches heterotrophs take to obtain nutrients? Give an example of each.
- Saprotroph - eat dead matter and feaces (wood louse)
- Necrotroph - kills then eats (lion, sheep)
- Biotroph - eats live without killing (parasite, tapeworm)
How do lions get rid of excess nitrogen and why?
Nitrogen-containing amine groups are toxic as they can raise cell pH levels. They are combined with CO2 to create urea which is neutral. This is then excreted via the kidneys as urine.
How to mangroves cope with excess salt in water?
Salts are excreted by glands on leaf to form crystals. This maintains osmoregulation within the cells.
How do terrestrial trees get rid of excess nutrients?
Senescing leaves contain unwanted solutes, toxins and organic compounds. These fall in autumn, or at other times if required.
What similarity exists between fungi and mammals that get rid of unwanted compounds?
Mammals excrete toxic metals in dead matter such as nails and hair.
Fungi excrete them in old tissue, such as dying hyphae
What two ways can energy be released from an organism?
- The organism releases it for energy use.
2. The organism gets eaten and the energy passes up the food chain.
What are the three main components of macronutrients?
Carbon, hydrogen + oxygen = carbohydrates
How/where is energy stored in molecules?
Mainly in the C-C bonds that hold carbon atoms together
Explain the differences between carbohydrates and lipids with respect to solubility and formation.
Lipids (fats and oils) are hydrophobic (insoluble in water) and aggregate together to form droplets.
Carbohydrates are hydrophilic (water soluble) and polymerise into long-chain molecules.
Where might TAGs be found in (a) plants & (b) animals:
(a) as oils in seeds, giving an energy reserve for seedings
(b) as adipose tissue in animals, as a fat/energy store
Where are short and long term energy reserves kept in animals and what are they?
Short = glycogen - kept in liver and muscles Long = TAGs in adipose tissue
Why are TAGs more efficient energy stores than glycogen?
As they are hydrophobic, TAGs don’t contain water and are therefore 6x denser. Per unit mass they are therefore much more efficient as energy stores.
